The Vascular‐Immune Cells Crosstalk and Microenvironment in Pulmonary Hypertension

Figures

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  FIGURE 1. Endothelial and smooth muscle cells diseased phenotypes. Illustration shows comparisons between the healthy function of endothelial and smooth muscle cells versus their pathological status. As observed, endothelial cells, under physiological conditions, maintain a balanced vasoactive modulation and regulate cellular adhesion and host defense. However, under the exposure of certain external stimuli, they undergo a transition towards a mesenchymal phenotype, exhibiting higher production of vasoconstrictors and a pro‐inflammatory and pro‐thrombotic state. These events characterize the dysfunctional endothelium, which secretes molecules such as chemokines and cytokines that exacerbate the vascular remodeling. On the other hand, smooth muscle cells suffer from a shift towards a synthetic phenotype, responsible for a vascular repair function, increasing their proliferative and migratory capacities.

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  FIGURE 2. Cell‐to‐cell communication between ECs, VSMCs, fibroblasts and immune cells in vascular remodeling. Illustration shows interactions between ECs (in blue), VSMCs (in red), fibroblasts (in brown) and immune cells (in purple). Speech bubbles in yellow indicate external stimuli affecting the target cells; gray dotted lines designate molecules that are secreted; blue, red, and brown dotted lines indicate the association between a molecule or signaling pathway and its pathogenic effects in ECs, VSMCs, and fibroblasts, respectively; straight blue and red lines represent downstream effectors in ECs and VSMCs, respectively.